The rifamycins, a group of closely related antibiotics, are described by Sensi et al.: Farmaco, Ed. Sci. 14, 146 (1959); Antibiotics Ann. 1959/1960, 262 (1960a); Experientia 16, 412 (1960b); Framaco, Ed. Sci. 16, 165 (1961); and Res. Progr. Org. Biol. Med. Chem. 1, 337 (1964).
The constitution of the rifamycins was established by Prelog, V., Pure Appl. Chem. 7,511 (1963b). Prelog coined the term "ansamycin" to refer to this particular class of large molecule antibiotics.